1) Field of the Invention
This invention relates to an improvement in an automotive vehicle equipped with an air bag system, and especially to the discharge of a gas, which has been generated upon actuation of the air bag system, from a vehicle interior into the outside.
2) Description of the Related Art
As a cushioning system for providing additional safety beyond that provided by a seat belt system for holding safely an occupant or the like of an automotive vehicle, an air bag system has been put into practical use. With the air bag system, the body of an occupant, especially his head and chest, is supported by a balloon-like air bag in the event of a collision and the internal gas is then gradually discharged, whereby a cushioning stroke is prolonged to reduce impact to the body.
Such an air bag system includes a module constructed of a center pad, a folded air bag, an inflator (gas generator) and the like. The module can be built into a steering wheel, for example. When triggered by an electric signal from a sensor which has detected a vehicular collision, the inflator is activated so that the air bag is instantaneously inflated by the resulting gas. After the air bag so inflated has supported as a cushioning member the head and chest of the occupant in the event of a collision, the gas is gradually released through a gas release hole formed in the air bag. As a result, impact to the occupant is reduced.
Such air bag systems include not only an air bag system for a driver's seat as described above but also an air bag system for a front passenger's seat or a rear passenger's seat. The air bag of the latter system has a greater volume than that of the former system. When all the air bag systems are actuated, the total volume of gas and smoke generated by inflators of the respective air bag systems becomes substantial.
Incidentally, gas and smoke produced from a detonator of each inflator to inflate its associated air bag contain components which give discomfort to passengers. Especially when the ventilation of an automotive vehicle is in a naturally-ventilated state (i.e., in a state not forcedly ventilated with the exterior air), an opening through which the vehicle interior is in communication with the exterior air is extremely small so that the gas filled in the vehicle interior can be hardly discharged into the outside of the automotive vehicle. This leads to the problem that the gas and smoke released from the air bags remain at high concentrations inside the vehicle interior.